Azeotrope-like compositions of tetrafluoropropene and hydrofluorocarbons

ABSTRACT

Provided are azeotrope-like compositions comprising tetrafluoropropene and hydrofluorocarbons and uses thereof, including use in refrigerant compositions, refrigeration systems, blowing agent compositions, and aerosol propellants.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Divisional of U.S. application Ser. No.13/429,806, filed on Mar. 26, 2012 (now allowed), which is aContinuation of U.S. application Ser. No. 12/511,018, filed on Jul. 28,2009 (now U.S. Pat. No. 8,148,317), which is a Divisional of U.S.application Ser. No. 11/119,053 filed on Apr. 29, 2005 (now U.S. Pat.No. 7,767,638), which is a Continuation-in-Part of U.S. application Ser.No. 10/837,526 filed on Apr. 29, 2004 (now U.S. Pat. No. 7,524,805), allof which are incorporated by reference.

The present application is also related to and incorporates by referenceeach of the following United States Patent Applications: U.S.application Ser. No. 10/837,525, filed Apr. 29, 2004; Ser. No.10/837,521, filed Apr. 29, 2004, Ser. No. 10/694,273, filed Oct. 27,2003; Ser. No. 10/695,212, filed Oct. 27, 2003; and Ser. No. 10/694,272filed Oct. 27, 2003.

The present application is related to and incorporates by reference eachof the following U.S. Provisional Applications: 60/567,426; 60/567,429;60/567,427; 60/567,425 and 60/567,428, all of which were filed on Apr.29, 2004.

FIELD OF INVENTION

The present invention relates generally to compositions comprising1,1,3,3-tetrafluoropropene. More specifically, the present inventionprovides azeotrope-like compositions comprising1,1,1,3-tetrafluoropropene and uses thereof.

BACKGROUND

Fluorocarbon based fluids have found widespread use in industry in anumber of applications, including as refrigerants, aerosol propellants,blowing agents, heat transfer media, and gaseous dielectrics. Because ofthe suspected environmental problems associated with the use of some ofthese fluids, including the relatively high global warming potentialsassociated therewith, it is desirable to use fluids having low or evenzero ozone depletion potential, such as hydrofluorocarbons (“HFCs”).Thus, the use of fluids that do not contain chlorofluorocarbons (“CFCs”)or hydrochlorofluorocarbons (“HCFCs”) is desirable. Furthermore, someHFC fluids may have relatively high global warming potentials associatedtherewith, and it is desirable to use hydrofluorocarbon or otherfluorinated fluids having global warming potentials as low as possiblewhile maintaining the desired performance in use properties.Additionally, the use of single component fluids or azeotrope-likemixtures, which do not substantially fractionate on boiling andevaporation, is desirable. However, the identification of new,environmentally-safe, non-fractionating mixtures is complicated due tothe fact that azeotrope formation is not readily predictable.

The industry is continually seeking new fluorocarbon based mixtures thatoffer alternatives, and are considered environmentally safer substitutesfor CFCs and HCFCs. Of particular interest are mixtures containing bothhydrofluorocarbons and other fluorinated compounds, both of low ozonedepletion potentials. Such mixtures and their uses are the subject ofthis invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

The present inventors have developed several compositions that help tosatisfy the continuing need for alternatives to CFCs and HCFCs.According to certain embodiments, the present invention providesazeotrope-like compositions comprising, or consisting essentially of,1,1,1,3-tetrafluoropropene (“HFO-1234ze”), preferablytrans-1,1,1,3-tetrafluoropropene (“transHFO-1234ze”) and at least onecompound component selected from the group consisting of1,1-difluoroethane (“HFC-152a”), 1,1,1,2,3,3,3-heptafluoropropane(“HFC-227ea”), 1,1,1,2,-tetraafluoethane (“HFC-134a”),1,1,1,2,2-pentafluoroethane (“HFC-125”) and combinations of two or moreof these. Thus, the present invention overcomes the aforementionedshortcomings by providing azeotrope-like compositions that are, inpreferred embodiments, substantially free of CFCs and HCFCs and whichexhibit relatively constant boiling point and vapor pressurecharacteristics.

The preferred compositions of the invention tend to exhibitcharacteristics which make them particularly desirable for use in anumber of applications, including as refrigerants in automotive airconditioning and heat pump systems, and in stationary air conditioningand refrigeration. In particular, applicants have recognized that thepresent compositions tend to exhibit relatively low global warmingpotentials (“GWPs”), preferably less than about 1000, more preferablyless than about 500, and even more preferably less than about 150.Preferred embodiments of the present compositions tend also to havesimilar or higher refrigeration capacity than many conventional HFCrefrigerants, for example, HFC-134a. Accordingly, applicants haverecognized that such compositions can be used to great advantage in anumber of applications, including as replacements for CFCs such asdichlorodifluormethane (CFC-12), HCFCs, such as chlorodifluoromethane(HCFC-22), and HFCs, such as tetrafluoroethane (HFC-134a) andcombinations of HFCs and CFCs, such as the combination of CFC-12 and1,1-difluorethane (HFC-152a) (the combination CFC-12:HFC-152a in a73.8:26.2 mass ratio being known as R-500) in refrigerant, aerosol, andother applications.

Additionally, applicants have recognized surprisingly that theazeotrope-like compositions of the present invention exist and can bereadily formed in view of the teachings contained herein. Accordingly,one aspect of the present invention provides methods of producingazeotrope-like compositions comprising the step of combining HFO-1234,preferably HFO-1234ze, and even more preferably transHFO-1234ze, and acompound selected from the group consisting of 1,1-difluoroethane(“HFC-152a”), 1,1,1,2,3,3,3-heptafluoropropane (“HFC-227ea”),1,1,1,2,-tetraafluoethane (“HFC-134a”), 1,1,1,2,2-pentafluoroethane(“HFC-125”) and combinations of two or more of these, in amountseffective to produce an azeotrope-like composition.

The term “HFO-1234” is used herein to refer to all tetrafluoropropenes.Among the tetrafluoropropenes are included HFO-1234yf and both cis- andtrans-1,3,3,3-tetrafluoropropene (HFO-1234ze). The term HFO-1234ze isused herein generically to refer to 1,3,3,3-tetrafluoropropene,independent of whether it is the cis- or trans-form. The terms“cisHFO-1234ze” and “transHFO-1234ze” are used herein to describe thecis- and trans-forms of 1,3,3,3-tetrafluoropropene respectively. Theterm “HFO-1234ze” therefore includes within its scope cisHFO-1234ze,transHFO-1234ze, and all combinations and mixtures of these.

Although the properties of cisHFO-1234ze and transHFO-1234ze differ inat least some respects, and while the present azeotrope-likecompositions are based mainly on transHFO-1234ze, it is contemplatedthat the cisHFO-1234ze form may be present in certain embodiments inamounts which do not negate the essential nature of the azeotrope-likecomposition. Accordingly, it is to be understood that the terms“HFO-1234ze” and 1,3,3,3-tetrafluoropropene refer to both stereoisomers, and the use of this term is intended to indicate that each ofthe cis- and trans-forms applies and/or is useful for the stated purposeunless otherwise indicated.

HFO-1234 compounds are known materials and are listed in ChemicalAbstracts databases. The production of fluoropropenes such as CF3CH═CH2by catalytic vapor phase fluorination of various saturated andunsaturated halogen-containing C3 compounds is described in U.S. Pat.Nos. 2,889,379; 4,798,818 and 4,465,786, each of which is incorporatedherein by reference. EP 974,571, also incorporated herein by reference,discloses the preparation of 1,1,1,3-tetrafluoropropene by contacting1,1,1,3,3-pentafluoropropane (HFC-245fa) in the vapor phase with achromium-based catalyst at elevated temperature, or in the liquid phasewith an alcoholic solution of KOH, NaOH, Ca(OH)2 or Mg(OH)2. Inaddition, methods for producing compounds in accordance with the presentinvention are described generally in connection with pending UnitedStates Patent Application entitled “Process for ProducingFluoropropenes”, which is also incorporated herein by reference.

In addition, applicants have recognized that the azeotrope-likecompositions of the present invention exhibit properties that make themadvantageous for use as, or in, numerous applications, including as heattransfer compositions (including as refrigerants in automotive airconditioning and heat pump systems, and in stationary air conditioning,heat pump and refrigeration systems), blowing agents, propellants andsterilizing agents. Accordingly, yet other aspects of the presentinvention provide one or more azeotrope-like compositions of the presentinvention and methods associated with these and other uses.

In another embodiment, the compositions of this invention may be used aspropellants in sprayable compositions, either alone or in combinationwith known propellants. The propellant compositions comprise, morepreferably consists essentially of, and, even more preferably consist ofthe compositions of the invention. The active ingredient to be sprayedtogether with inert ingredients, solvents, and other materials may alsobe present in the sprayable mixture. Preferably, the sprayablecomposition is an aerosol. Suitable active materials to be sprayedinclude, without limitation, cosmetic materials such as deodorants,perfumes, hair sprays, cleaning solvents, lubricants, as well asmedicinal materials such as anti-asthma medications.

The present compositions find particular advantage in methods andsystems involving aerosol compositions, particularly in medicinalcompositions, cleaning composition, and other sprayable compositions.Those of skill in the art will be readily able to adapt the presentcompositions for use in such applications without undue experimentation.

Azeotrope-Like Compositions

As used herein, the term “azeotrope-like” is intended in its broad senseto include both compositions that are strictly azeotropic andcompositions that behave like azeotropic mixtures. From fundamentalprinciples, the thermodynamic state of a fluid is defined by pressure,temperature, liquid composition, and vapor composition. An azeotropicmixture is a system of two or more components in which the liquidcomposition and vapor composition are equal at the stated pressure andtemperature. In practice, this means that the components of anazeotropic mixture are constant-boiling and cannot be separated during aphase change.

Azeotrope-like compositions are constant boiling or essentially constantboiling. In other words, for azeotrope-like compositions, thecomposition of the vapor formed during boiling or evaporation isidentical, or substantially identical, to the original liquidcomposition. Thus, with boiling or evaporation, the liquid compositionchanges, if at all, only to a minimal or negligible extent. This is tobe contrasted with non-azeotrope-like compositions in which, duringboiling or evaporation, the liquid composition changes to a substantialdegree. All azeotrope-like compositions of the invention within theindicated ranges as well as certain compositions outside these rangesare azeotrope-like.

The azeotrope-like compositions of the invention may include additionalcomponents that do not form new azeotrope-like systems, or additionalcomponents that are not in the first distillation cut. The firstdistillation cut is the first cut taken after the distillation columndisplays steady state operation under total reflux conditions. One wayto determine whether the addition of a component forms a newazeotrope-like system so as to be outside of this invention is todistill a sample of the composition with the component under conditionsthat would be expected to separate a non-azeotropic mixture into itsseparate components. If the mixture containing the additional componentis non-azeotrope-like, the additional component will fractionate fromthe azeotrope-like components. If the mixture is azeotrope-like, somefinite amount of a first distillation cut will be obtained that containsall of the mixture components that is constant boiling or behaves as asingle substance.

It follows from this that another characteristic of azeotrope-likecompositions is that there is a range of compositions containing thesame components in varying proportions that are azeotrope-like orconstant boiling. All such compositions are intended to be covered bythe terms “azeotrope-like” and “constant boiling”. As an example, it iswell known that at differing pressures, the composition of a givenazeotrope will vary at least slightly, as does the boiling point of thecomposition. Thus, an azeotrope of A and B represents a unique type ofrelationship, but with a variable composition depending on temperatureand/or pressure. It follows that, for azeotrope-like compositions, thereis a range of compositions containing the same components in varyingproportions that are azeotrope-like. All such compositions are intendedto be covered by the term azeotrope-like as used herein.

It is well-recognized in the art that it is not possible to predict theformation of azeotropes. (See, for example, U.S. Pat. No. 5,648,017(column 3, lines 64-65) and U.S. Pat. No. 5,182,040 (column 3, lines62-63), both of which are incorporated herein by reference). Applicantshave discovered unexpectedly that HFO-1234 and HFCs, particularly theHFCs described above, form azeotrope-like compositions.

According to certain preferred embodiments, the azeotrope-likecompositions of the present invention comprise, and preferably consistessentially of, effective amounts of HFO-1234 and the above-noted HFCs.The term “effective amounts” as used herein refers to the amount of eachcomponent which upon combination with the other component, results inthe formation of an azeotrope-like composition of the present invention.

The azeotrope-like compositions of the present invention can be producedby combining effective amounts of HFO-1234 and a component, preferablyin fluid form, selected from the group consisting of 1,1-difluoroethane(“HFC-152a”), 1,1,1,2,3,3,3-heptafluoropropane (“HFC-227ea”),1,1,1,2,-tetrafluoroethane (“HFC-134a”), 1,1,1,2,2-pentafluoroethane(“HFC-125”) and combinations of two or more of these. Any of a widevariety of methods known in the art for combining two or more componentsto form a composition can be adapted for use in the present methods toproduce an azeotrope-like composition. For example, transHFO-1234ze andHFC-152a can be mixed, blended, or otherwise combined by hand and/or bymachine, as part of a batch or continuous reaction and/or process, orvia combinations of two or more such steps. In light of the disclosureherein, those of skill in the art will be readily able to prepareazeotrope-like compositions according to the present invention withoutundue experimentation.

Preferably, such azeotrope-like compositions comprise, preferablyconsist essentially of, from greater than zero to about 99 wt. % ofHFO-1234, preferably transHFO-1234ze, and from about 1 wt. % to lessthan 100 wt. % of one or more components selected from the groupconsisting 1,1-difluoroethane (“HFC-152a”),1,1,1,2,3,3,3-heptafluoropropane (“HFC-227ea”),1,1,1,2,-tetrafluoroethane (“HFC-134a”), and 1,1,1,2,2-pentafluoroethane(“HFC-125”). It will be appreciated by those skilled in the art that theproduction transHFO-1234ze will commonly result in product whichincludes a small proportion of compound which are not transHFO-1234ze.For example, it would be common in expected for a product designated astransHFO-1234ze to include a minor percentage, for example about 0.5 wt.% up to about 1 wt. % of other components, including particularlycisHFO-1234ze and/or HFO-1234yf. The term “consisting essentially oftransHFO-1234ze” used herein is intended to generally include suchcompositions.

More preferably, the present azeotrope-like compositions comprise, andpreferably consist essentially of, from about 5 wt. % to about 90 wt. %of HFO-1234, preferably transHFO-1234ze, and from about 10 wt. % toabout 90 wt. % of one or more components selected from the groupconsisting of 1,1-difluoroethane (“HFC-152a”),1,1,1,2,3,3,3-heptafluoropropane (“HFC-227ea”),1,1,1,2,-tetrafluoroethane (“HFC-134a”), and 1,1,1,2,2-pentafluoroethane(“HFC-125”). Other preferred compositions comprise, or consistessentially of, greater than zero to about 60 wt. % of HFO-1234,preferably transHFO-1234ze, and from about 40 wt. % to less than 100 wt.% of one or more components selected from the group consisting1,1-difluoroethane (“HFC-152a”), 1,1,1,2,3,3,3-heptafluoropropane(“HFC-227ea”), 1,1,1,2,-tetrafluoroethane (“HFC-134a”), and1,1,1,2,2-pentafluoroethane (“HFC-125”). Unless otherwise indicated, allweight percents reported herein are based on the total weight of theHFO-1234 and the one or more components selected from the indicatedgroup in the azeotrope-like composition.

According to certain preferred embodiments, the present transHFO-1234zeazeotrope-like compositions have a boiling point of from about −15° C.to about −50° C., and even more preferably from about −28° C. to about−50° C., at about 14 psia. In certain preferred embodiments, the presentcompositions have a boiling point of about −23° C.±2° C. In otherpreferred embodiments, the present compositions have a boiling point ofabout −18° C.±1° C. Additionally, in other preferred embodiments thepresent compositions have a boiling point of about −47° C.±2° C.Preferably, the HFO-1234 containing compositions of the presentinvention are substantially homogenous azeotrope-like compositions.

HFO-1234/HFC-134a

Certain preferred embodiments of the present invention provideazeotrope-like compositions comprising transHFO-1234ze and HFC-134a.Preferably, the novel azeotrope-like compositions of the presentinvention comprise effective amounts of transHFO-1234ze and HFO-134a.These embodiments preferably provide azeotrope-like compositionscomprising, and preferably consisting essentially of, from greater thanzero to about 75 weight percent transHFO-1234ze and from about 25 wt. %to less than 100 wt. % HFC-134a, more preferably from greater than zeroto about 60 wt. % transHFO-1234ze and from about 40 wt. % to less than100 wt. % HFO-134a, and even more preferably from about 1% to about 40weight percent transHFO-1234ze and from about 60 wt. % to about 99 wt. %HFC-134a. In certain preferred embodiments, the azeotrope-likecompositions comprise, and preferably consist essentially of, from about5 wt. % to about 35 wt % transHFO-1234ze and from about 65 wt. % toabout 95 wt. % HFO-134a.

Preferably, the HFO-1234/HFC-134a compositions of the present inventionhave a boiling of from about −26° C. to about −23° C. at about 14 psia.

Preferably, the HFO-1234/HFO-134a compositions of the present inventionhave a boiling of about −25° C.±3° C. at about 14 psia. In certainembodiments, the compositions have a boiling point of preferably about−25° C.±2° C., and even more preferably −25° C.±1° C., all measured atabout 14 psia.

Preferably the HFO-1234 of these embodiments is transHFO-1234ze.

HFO-1234/HFC-125

In certain other preferred embodiments, the present invention providesazeotrope-like compositions comprising transHFO-1234ze and HFC-125.Preferably, such novel azeotrope-like compositions of the presentinvention comprise, or consist essentially of, effective amounts oftransHFO-1234ze and HFC-125. These embodiments preferably provideazeotrope-like compositions comprising, and preferably consistingessentially of, from greater than zero to about 99 weight percenttransHFO-1234ze and from about 1 wt. % to less than 100 wt. % HFC-125,more preferably from greater than zero to about 75 wt. % transHFO-1234zeand from about 25 wt. % to less than 100 wt. % HFC-125, even morepreferably from about greater than zero to about 60 wt. %transHFO-1234ze and from about 40 to less than 100 wt. % HFC-125, andeven more preferably from about 1% to about 40 weight percenttransHFO-1234ze and from about 60 wt. % to about 99 wt. % HFC-125. Incertain preferred embodiments, the azeotrope-like compositions comprise,and preferably consist essentially of, from about 2 wt. % to about 15 wt% transHFO-1234ze and from about 85 wt. % to about 98 wt. % HFO-125.

Other preferred compositions comprise, or consist essentially of, fromgreater than zero to about 45 wt. % transHFO-1234ze and from about 55 toless than 100 wt. % HFC-125.

Preferably, the HFO-1234/HFC-125 compositions of the present inventionhave a boiling of about −44° C. to about −50° C., at about 14 psia.

Preferably the HFO-1234/HFC-125 compositions of the present inventionhave a boiling of about −47° C.±2° C., preferably −47° C.±1° C. at about14 psia.

HFO-1234/HFC-152a

In certain other preferred embodiments, the present invention providesazeotrope-like compositions comprising transHFO-1234ze and HFC-152a.Preferably, such novel azeotrope-like compositions of the presentinvention comprise, or consist essentially of, effective amounts oftransHFO-1234ze and HFC-152a. These embodiments preferably provideazeotrope-like compositions comprising, and preferably consistingessentially of, from greater than zero to about 99 weight percenttransHFO-1234ze and from about 1 wt. % to less than 100 wt. % HFC-152a,more preferably from greater than zero to about 50 wt. % transHFO-1234zeand from about 50 wt. % to less than 100 wt. % HFC-152a, and even morepreferably from about greater than zero to about 40 wt. %transHFO-1234ze and from about 60% to less than 100 wt. % HFC-227ea. Incertain preferred embodiments, the azeotrope-like compositions comprise,and preferably consist essentially of, from about 15 wt. % to about 30wt % transHFO-1234ze and from about 70 wt. % to about 85 wt. % HFO-152a.

Preferably, the HFO-1234/HFC-152a compositions of the present inventionhave a boiling of from about −22° C. to about −24° C. at about 14 psia.

Preferably, the HFO-1234/HFO-152a compositions of the present inventionhave a boiling of about −23° C.±2° C. at about 14 psia. In certainembodiments, the compositions have a boiling point of preferably about−23° C.±1° C. measured at about 14 psia.

Preferably the HFO-1234 of these embodiments is transHFO-1234ze.

HFO-1234/HFC-227ea

Certain preferred embodiments of the present invention provideazeotrope-like compositions comprising transHFO-1234ze and HFC-227ea.Preferably, the novel azeotrope-like compositions of the presentinvention comprise effective amounts of transHFO-1234ze and HFO-227ea.These embodiments preferably provide azeotrope-like compositionscomprising, and preferably consisting essentially of, from greater thanzero to about 75 weight percent HFC-227ea and from about 25 wt. % toless than 100 wt. % transHFO-1234ze, more preferably from greater thanzero to about 60 wt. % HFC-227ea and from about 40 wt. % to less than100 wt. % transHFC-1234ze, and even more preferably from about 1% toabout 40 weight percent HFC-227ea and from about 60 wt. % to about 99wt. % transHFO-1234ze. In certain preferred embodiments, theazeotrope-like compositions comprise, and preferably consist essentiallyof, from about 5 wt. % to about 35 wt % HFC-227ea and from about 65 wt.% to about 95 wt. % transHFO-1234ze.

Preferably, the HFO-1234/HFC-227ea compositions of the present inventionhave a boiling of from about −17° C. to about −19° C. at about 14 psia.

Preferably, the HFO-1234/HFO-227ea compositions of the present inventionhave a boiling of about −18° C.±2° C. at about 14 psia, and even morepreferably about −18° C.±1° C., measured at about 14 psia.

Preferably the HFO-1234 of these embodiments is transHFO-1234ze.

Composition Additives

The azeotrope-like compositions of the present invention may furtherinclude any of a variety of optional additives including lubricants,stabilizers, metal passivators, corrosion inhibitors, flammabilitysuppressants, and the like.

According to certain embodiments, the azeotrope-like compositions of thepresent invention further comprise a stabilizer. Any of a variety ofcompounds suitable for stabilizing an azeotrope-like composition of thepresent invention may be used. Examples of certain preferred stabilizersinclude stabilizer compositions comprising stabilizing diene-basedcompounds, and/or phenol compounds, and/or epoxides selected from thegroup consisting of aromatic epoxides, alkyl epoxides, alkenyl epoxides,and combinations of two or more thereof.

In certain preferred embodiments, the compositions of the presentinvention further comprise a lubricant. Any of a variety of conventionaland unconventional lubricants may be used in the compositions of thepresent invention. An important requirement for the lubricant is that,when in use in a refrigerant system, there must be sufficient lubricantreturning to the compressor of the system such that the compressor islubricated. Thus, suitability of a lubricant for any given system isdetermined partly by the refrigerant/lubricant characteristics andpartly by the characteristics of the system in which it is intended tobe used. Examples of suitable lubricants include, which are generallythose commonly used in refrigeration machinery using or designed to usehydrofluorocarbon (HFC) refrigerants, chlorofluorocarbon refrigerantsand hydrochlorofluorocarbons refrigerants, include mineral oil, siliconeoil, polyalkyl benzenes (sometimes referred to as (PABs), polyol esters(sometimes referred to as (POEs), polyalkylene glycols (sometimesreferred to as (PAGs), polyalkylene glycol esters (sometimes referred toas PAG esters), polyvinyl ethers (sometimes referred to as PVEs),poly(alpha-olefin) (sometimes referred to as PAOs) and halocarbon oils,particularly poly(chlorotrifluorethylene) and the like. Mineral oil,which comprises paraffin oil or naphthenic oil, is commerciallyavailable. Commercially available mineral oils include Witco LP 250(registered trademark) from Witco, Zerol 300 (registered trademark) fromShrieve Chemical, Sunisco 3GS from Witco, and Calumet R015 from Calumet.Commercially available polyalkyl benzene lubricants include Zerol 150(registered trademark). Commercially available esters include neopentylglycol dipelargonate which is available as Emery 2917 (registeredtrademark) and Hatcol 2370 (registered trademark). Commerciallyavailable PAGs include Motorcraft PAG Refrigerant Compressor Oil,available from Ford, with similar products being available from Dow.Commercially available PAOs include CP-4600 from CPI Engineering.Commercially available PVEs are available from Idemitsu Kosan.Commercially available PAG esters are available from Chrysler. Otheruseful esters include phosphate esters, dibasic acid esters, andfluoroesters.

For refrigeration systems using or designed to use HFCs, it is generallypreferred to use as lubricants PAGs, PAG esters, PVEs, and POEs,particularly for systems comprising compression refrigeration,air-conditioning (especially for automotive air conditioning) and heatpumps. For refrigeration systems using or designed to use CFCs or HCFCs,it is generally preferred to use as lubricants mineral oil or PAB. Incertain preferred embodiments, the lubricants of this invention areorganic compounds which are comprised of carbon, hydrogen and oxygenwith a ratio of oxygen to carbon and are included to provide, incombination with the amounts used, effective solubility and/ormiscibility with the refrigerant to ensure sufficient return of thelubricant to the compressor. This solubility or miscibility preferablyexists at at least one temperature from about −30° C. and 70° C.

PAGs and PAG esters are highly preferred in certain embodiments becausethey are currently in use in particular applications such as originalequipment mobile air-conditioning systems. Polyol esters are highlypreferred in other certain embodiments because they are currently in usein particular non-mobile applications such as residential, commercial,and industrial air conditioning and refrigeration. Of course, differentmixtures of different types of lubricants may be used.

Uses of the Compositions

The present compositions have utility in a wide range of applications.For example, one embodiment of the present invention relates to heattransfer compositions, such as refrigerant compositions, comprising anazeotrope-like composition of the present invention. The heat transfercompositions of the present invention are generally adaptable for use inheat transfer applications, that is, as a heating and/or cooling medium.Although it is contemplated that the compositions of the presentinvention may include the present azeotrope-like composition incombination with one or more other compounds or combinations ofcompounds in widely ranging amounts, it is generally preferred that heattransfer compositions of the present invention, including refrigerantcompositions, consist essentially of, and in some embodiments consist ofthe present azeotrope-like compositions.

The heat transfer compositions of the present invention may be used inany of a wide variety of refrigeration systems includingair-conditioning (including both stationary and mobile air conditioningsystems), refrigeration, heat-pump systems, and the like. In certainpreferred embodiments, the compositions of the present invention areused in refrigeration systems originally designed for use with anHFC-refrigerant, such as, for example, HFC-134a or an HCFC refrigerant,such as, for example, HCFC-22. The preferred compositions of the presentinvention tend to exhibit many of the desirable characteristics ofHFC-134a and other HFC-refrigerants, including non-flammability, and aGWP that is as low, or lower than that of conventional HFC-refrigerantsand a capacity that is as substantially similar to or substantiallymatches, and preferably is as high as or higher than such refrigerants.In particular, applicants have recognized that the present compositionstend to exhibit relatively low global warming potentials (“GWPs”),preferably less than about 1000, more preferably less than about 500,and even more preferably less than about 150. In addition, therelatively constant boiling nature of the compositions of the presentinvention makes them even more desirable than certain conventional HFCs,such as R-404A or combinations of HFC-32, HFC-125 and HFC-134a (thecombination HFC-32:HFC-125:HFC134a in approximate 23:25:52 weight ratiois referred to as R-407C), for use as refrigerants in many applications.Heat transfer compositions of the present invention are particularlypreferred as replacements for HFC-134, HFC-152a, HFC-22, R-12 and R-500.The present compositions are also believed to be suitable asreplacements for the above noted compositions in other applications,such as aerosols, blowing agents and the like.

In certain other preferred embodiments, the present compositions areused in heat transfer systems in general, and in refrigeration systemsin particular, originally designed for use with a CFC-refrigerant.Preferred refrigeration compositions of the present invention may beused in refrigeration systems containing a lubricant used conventionallywith CFC-refrigerants, such as mineral oils, polyalkylbenzene,polyalkylene glycols, and the like, or may be used with other lubricantstraditionally used with HFC refrigerants.

As used herein the term “refrigeration system” refers generally to anysystem or apparatus, or any part or portion of such a system orapparatus, which employs a refrigerant to provide cooling. Suchrefrigeration systems include, for example, air conditioners, electricrefrigerators, chillers (including chillers using centrifugalcompressors), transport refrigeration systems, commercial refrigerationsystems and the like.

In certain embodiments, the compositions of the present invention may beused to retrofit refrigeration systems containing HFC, HCFC, and/orCFC-refrigerants and lubricants used conventionally therewith.Preferably, the present methods involve recharging a refrigerant systemthat contains a refrigerant to be replaced and a lubricant comprisingthe steps of (a) removing the refrigerant to be replaced from therefrigeration system while retaining a substantial portion of thelubricant in said system; and (b) introducing to the system acomposition of the present invention. As used herein, the term“substantial portion” refers generally to a quantity of lubricant whichis at least about 50% (by weight) of the quantity of lubricant containedin the refrigeration system prior to removal of the chlorine-containingrefrigerant. Preferably, the substantial portion of lubricant in thesystem according to the present invention is a quantity of at leastabout 60% of the lubricant contained originally in the refrigerationsystem, and more preferably a quantity of at least about 70%. As usedherein the term “refrigeration system” refers generally to any system orapparatus, or any part or portion of such a system or apparatus, whichemploys a refrigerant to provide cooling. Such refrigeration systemsinclude, for example, air conditioners, electric refrigerators,chillers, transport refrigeration systems, commercial refrigerationsystems and the like.

Many existing refrigeration systems are currently adapted for use inconnection with existing refrigerants, and the compositions of thepresent invention are believed to be adaptable for use in many of suchsystems, either with or without system modification. In manyapplications the compositions of the present invention may provide anadvantage as a replacement in smaller systems currently based on certainrefrigerants, for example those requiring a small refrigerating capacityand thereby dictating a need for relatively small compressordisplacement. Furthermore, in embodiments where it is desired to use alower capacity refrigerant composition of the present invention, forreasons of efficiency for example, to replace a refrigerant of highercapacity, such embodiments of the present compositions provide apotential advantage. Thus, it is preferred in certain embodiments to usecompositions of the present invention, particularly compositionscomprising a substantial proportion of, and in some embodimentsconsisting essentially of the present azeotrope-like compositions, as areplacement for existing refrigerants, such as: HFC-134a; CFC-12;HCFC-22; HFC-152a; combinations of pentfluoroethane (HFC-125),trifluorethane (HFC-143a) and tetrafluoroethane (HFC-134a) (thecombination HFC-125:HFC-143a:HFC134a in approximate 44:52:4 weight ratiois referred to as R-404A); combinations of HFC-32, HFC-125 and HFC-134a(the combination HFC-32:HFC-125:HFC134a in approximate 23:25:52 weightratio is referred to as R-407C); combinations of methylene fluoride(HFC-32) and pentfluoroethane (HFC-125) (the combination HFC-32:HFC-125in approximate 50:50 weight ratio is referred to as R-410A); thecombination of CFC-12 and 1,1-difluorethane (HFC-152a) (the combinationCFC-12:HFC-152a in a 73.8:26.2 weight ratio is referred to R-500); andcombinations of HFC-125 and HFC-143a (the combination HFC-125:HFC143a inapproximate 50:50 weight ratio is referred to as R-507A). In certainembodiments it may also be beneficial to use the present compositions inconnection with the replacement of refrigerants formed from thecombination HFC-32:HFC-125:HFC134a in approximate 20:40:40 weight ratio,which is referred to as R-407A, or in approximate 15:15:70 weight ratio,which is referred to as R-407D. Heat transfer compositions of thepresent invention are particularly preferred as replacements for R-22,R-32, R-404A, R-407A, R-407C, R-407D, R-410A and R-507A. The presentcompositions are also believed to be suitable as replacements for theabove noted compositions in other applications, such as aerosols,blowing agents and the like.

In certain applications, the refrigerants of the present inventionpotentially permit the beneficial use of larger displacementcompressors, thereby resulting in better energy efficiency than otherrefrigerants, such as HFC-134a. Therefore the refrigerant compositionsof the present invention provide the possibility of achieving acompetitive advantage on an energy basis for refrigerant replacementapplications. It is contemplated that the compositions of the presentalso have advantage (either in original systems or when used as areplacement for refrigerants such as CFC-12, HCFC-22, HFC-134a, HFC-152aR-404A, R-410A, R-407C, R-500 and R-507A), in chillers typically used inconnection with commercial air conditioning and refrigeration systems.In certain of such embodiments it is preferred to including in thepresent compositions from about 0.5 to about 30%, and in certain casesmore preferably 0.5% to about 15% by weight of a supplementalflammability suppressant. In this regard it is noted that the HFO-1234zecomponent and the other compound in the azeotrope-like composition ofthe present compositions may in certain embodiments act as aflammability suppressant with respect to other components in thecomposition. For example, in cases where other components more flammablethan HFO-1234ze are included in the composition, HFO-1234-ze mayfunction to suppress the flammability of such other component. Thus, anyadditional components which have flammability suppressant functionalityin the composition will sometimes be referred to herein as asupplemental flammability suppressant.

In certain embodiments, co-refrigerants, including for example HFCs,HCFCs and CFCs may be included in the heat transfer compositions of thepresent invention, including one or more of the following compounds,including any and all isomers thereof:

Trichlorofluoromethane (CFC-11)

Dichlorodifluoromethane (CFC-12)

Difluoromethane (HFC-32)

1,1,1,3,3,3-hexafluoropropane (HFC-236fa)

1,1,1,3,3-pentafluoropropane (HFC-245fa)

1,1,1,3,3-pentafluorobutane (HFC-365mfc)

water

CO2

The relative amount of any of the above noted components, as well as anyadditional components which may be included in present compositions, maybe incorporated in amounts depending on the particular application forthe composition, and all such relative amounts are considered to bewithin the scope hereof, provided preferably that such components do notnegate the azeotrope-like nature of the preferred compositions describedherein.

The present methods, systems and compositions are thus adaptable for usein connection with automotive air conditioning systems and devices,commercial refrigeration systems and devices, chillers (includingsystems which utilize centrifugal compressors), residential refrigeratorand freezers, general air conditioning systems, heat pumps, and thelike.

Any of a wide range of known methods can be used to remove refrigerantsto be replaced from a refrigeration system while removing less than amajor portion of the lubricant contained in the system. For example,because refrigerants are quite volatile relative to traditionalhydrocarbon-based lubricants (the boiling points of refrigerants aregenerally less than 10° C. whereas the boiling points of mineral oilsare generally more than 200° C.), in embodiments wherein the lubricantis a hydrocarbon-based lubricant, the removal step may readily beperformed by pumping chlorine-containing refrigerants in the gaseousstate out of a refrigeration system containing liquid state lubricants.Such removal can be achieved in any of a number of ways known in theart, including, the use of a refrigerant recovery system, such as therecovery system manufactured by Robinair of Ohio. Alternatively, acooled, evacuated refrigerant container can be attached to the lowpressure side of a refrigeration system such that the gaseousrefrigerant is drawn into the evacuated container and removed. Moreover,a compressor may be attached to a refrigeration system to pump therefrigerant from the system to an evacuated container. In light of theabove disclosure, those of ordinary skill in the art will be readilyable to remove chlorine-containing lubricants from refrigeration systemsand to provide a refrigeration system having therein a hydrocarbon-basedlubricant and substantially no chlorine-containing refrigerant accordingto the present invention.

Any of a wide range of methods for introducing the present refrigerantcompositions to a refrigeration system can be used in the presentinvention. For example, one method comprises attaching a refrigerantcontainer to the low-pressure side of a refrigeration system and turningon the refrigeration system compressor to pull the refrigerant into thesystem. In such embodiments, the refrigerant container may be placed ona scale such that the amount of refrigerant composition entering thesystem can be monitored. When a desired amount of refrigerantcomposition has been introduced into the system, charging is stopped.Alternatively, a wide range of charging tools, known to those of skillin the art, is commercially available. Accordingly, in light of theabove disclosure, those of skill in the art will be readily able tointroduce the refrigerant compositions of the present invention intorefrigeration systems according to the present invention without undueexperimentation.

According to certain other embodiments, the present invention providesrefrigeration systems comprising a refrigerant of the present inventionand methods of producing heating or cooling by condensing and/orevaporating a composition of the present invention. In certain preferredembodiments, the methods for cooling including cooling of other fluideither directly or indirectly or a body directly or indirectly, comprisecondensing a refrigerant composition comprising an azeotrope-likecomposition of the present invention and thereafter evaporating saidrefrigerant composition in the vicinity of the fluid or body to becooled. Certain preferred methods for heating an article comprisecondensing a refrigerant composition comprising an azeotrope-likecomposition of the present invention in the vicinity of the fluid orbody to be heated and thereafter evaporating said refrigerantcomposition. As used herein, the term “body” is intended to refer notonly to inanimate objects but also to living tissue, including animaltissue in general and human tissue in particular. For example, certainaspects of the present invention involved application of the presentcomposition to human tissue for one or more therapeutic purposes, suchas a pain killing technique, as a preparatory anesthetic, or as part ofa therapy involving reducing the temperature of the body being treated.In certain embodiments, the application to the body comprises providingthe present compositions in liquid form under pressure, preferably in apressurized container having a one-way discharge valve and/or nozzle,and releasing the liquid from the pressurized container by spraying orotherwise applying the composition to the body. In light of thedisclosure herein, those of skill in the art will be readily able toheat and cool articles according to the present inventions without undueexperimentation.

Applicants have found that in the systems of the present invention manyof the important refrigeration system performance parameters arerelatively close to the parameters for R-134a. Since many existingrefrigeration systems have been designed for R-134a, or for otherrefrigerants with properties similar to R-134a, those skilled in the artwill appreciate the substantial advantage of a low GWP and/or a lowozone depleting refrigerant that can be used as replacement for R-134aor like refrigerants with relatively minimal modifications to thesystem. It is contemplated that in certain embodiments the presentinvention provides retrofitting methods which comprise replacing therefrigerant in an existing system with a composition of the presentinvention, without substantial modification of the system. In certainpreferred embodiments the replacement step is a drop-in replacement inthe sense that no substantial redesign of the system is required and nomajor item of equipment needs to be replaced in order to accommodate therefrigerant of the present invention. In certain preferred embodiments,the methods comprise a drop-in replacement in which the capacity of thesystem is at least about 70%, preferably at least about 85%, and evenmore preferably at least about 90% of the system capacity prior toreplacement. In certain preferred embodiments, the methods comprise adrop-in replacement in which the suction pressure and/or the dischargepressure of the system, and even more preferably both, is/are at leastabout 70%, more preferably at least about 90% and even more preferablyat least about 95% of the system capacity prior to replacement. Incertain preferred embodiments, the methods comprise a drop-inreplacement in which the mass flow of the system is at least about 80%,and even more preferably at least 90% of the system capacity prior toreplacement.

In another embodiment, the azeotrope-like compositions of this inventionmay be used as propellants in sprayable compositions, either alone or incombination with known propellants. The propellant compositioncomprises, more preferably consists essentially of, and, even morepreferably, consists of the azeotrope-like compositions of theinvention. The active ingredient to be sprayed together with inertingredients, solvents, and other materials may also be present in thesprayable mixture. Preferably, the sprayable composition is an aerosol.Suitable active materials to be sprayed include, without limitation,cosmetic materials such as deodorants, perfumes, hair sprays, andcleaning solvents, as well as medicinal materials such as anti-asthmamedications. The term medicinal materials is used herein in its broadestsense to include any and all materials which are, or at least arebelieve to be, effective in connection with therapeutic, diagnostic,pain relief, and similar treatments, and as such would include forexample drugs and biologically active substances.

Yet another embodiment of the present invention relates to a blowingagent comprising one or more azeotrope-like compositions of theinvention. In general, the blowing agent may include the azeotrope-likecompositions of the present invention in widely ranging amounts. It isgenerally preferred, however, that the blowing agents comprise thepresent azeotrope-like compositions in amounts at least about 5% byweight, and even more preferably at least about 15% by weight, of theblowing agent. In certain preferred embodiments, the blowing agentcomprises at least about 50% by weight of the present compositions, andin certain embodiments the blowing agent consists essentially of thepresent azeotrope-like composition. In certain preferred embodiments,the blowing agent includes, in addition to the present compositions, oneor more of co-blowing agents, fillers, vapor pressure modifiers, flamesuppressants, stabilizers and like adjuvants.

In other embodiments, the invention provides foamable compositions. Thefoamable compositions of the present invention generally include one ormore components capable of forming foam having a generally cellularstructure and a blowing agent in accordance with the present invention.In certain embodiments, the one or more components comprise athermosetting composition capable of forming foam and/or foamablecompositions. Examples of thermosetting compositions includepolyurethane and polyisocyanurate foam compositions, and also phenolicfoam compositions. and methods of preparing foams. In such thermosettingfoam embodiments, one or more of the present azeotrope-like compositionsare included as a blowing agent in a foamable composition, or as a partof a two or more part foamable composition, which composition preferablyincludes one or more additional components capable of reacting andfoaming under the proper conditions to form a foam or cellularstructure, as is well known in the art. In certain other embodiments,the one or more components comprise thermoplastic materials,particularly thermoplastic polymers and/or resins. Examples ofthermoplastic foam components include polyolefins, such as polystyrene(PS), polyethylene (PE), polypropylene (PP) and polyethyleneterepthalate(PET), and foams formed therefrom, preferably low-density foams. Incertain embodiments, the thermoplastic foamable composition is anextrudable composition.

It will be appreciated by those skilled in the art, especially in viewof the disclosure contained herein, that the order and manner in whichthe blowing agent of the present invention is formed and/or added to thefoamable composition does not generally affect the operability of thepresent invention. For example, in the case of extrudable foams, it ispossible that the various components of the blowing agent, and even thecomponents of the present composition, be not be mixed in advance ofintroduction to the extrusion equipment, or even that the components arenot added to the same location in the extrusion equipment. Thus, incertain embodiments it may be desired to introduce one or morecomponents of the blowing agent at first location in the extruder, whichis upstream of the place of addition of one or more other components ofthe blowing agent, with the expectation that the components will cometogether in the extruder and/or operate more effectively in this manner.Nevertheless, in certain embodiments, two or more components of theblowing agent are combined in advance and introduced together into thefoamable composition, either directly or as part of premix which is thenfurther added to other parts of the foamable composition.

The invention also relates to foam, and preferably closed cell foam,prepared from a polymer foam formulation containing a composition of theinvention, preferably as part of blowing agent.

In certain preferred embodiments, dispersing agents, cell stabilizers,surfactants and other additives may also be incorporated into theblowing agent compositions of the present invention. Surfactants areoptionally but preferably added to serve as cell stabilizers. Somerepresentative materials are sold under the names of DC-193, B-8404, andL-5340 which are, generally, polysiloxane polyoxyalkylene blockco-polymers such as those disclosed in U.S. Pat. Nos. 2,834,748,2,917,480, and 2,846,458, each of which is incorporated herein byreference. Other optional additives for the blowing agent mixture mayinclude flame retardants or suppressants such astri(2-chloroethyl)phosphate, tri(2-chloropropyl)phosphate,tri(2,3-dibromopropyl)-phosphate, tri(1,3-dichloropropyl) phosphate,diammonium phosphate, various halogenated aromatic compounds, antimonyoxide, aluminum trihydrate, polyvinyl chloride, and the like.

Any of the methods well known in the art, such as those described in“Polyurethanes Chemistry and Technology,” Volumes I and II, Saunders andFrisch, 1962, John Wiley and Sons, New York, N.Y., which is incorporatedherein by reference, may be used or adapted for use in accordance withthe foam embodiments of the present invention.

Other uses of the present azeotrope-like compositions include use assolvents, cleaning agents, and the like. Those of skill in the art willbe readily able to adapt the present compositions for use in suchapplications without undue experimentation.

EXAMPLES

The invention is further illustrated in the following example which isintended to be illustrative, but not limiting in any manner. Forexamples 1-4, a ebulliometer of the general type described bySwietolslowski in his book Ebulliometric Measurements (Reinhold, 1945)was used.

Example 1

An ebulliometer consisting of vacuum jacketed tube with a condenser ontop which is further equipped with a Quartz Thermometer is used. About21 g HFC-134a is charged to the ebulliometer and then HFO-1234ze isadded in small, measured increments. Temperature depression is observedwhen HFO-1234 is added to HFC-134a, indicating a binary minimum boilingazeotrope is formed. From greater than about 0 to about 51 weightpercent HFO-1234ze, the boiling point of the composition changed byabout 1.3° C. or less. The binary mixtures shown in Table 1 were studiedand the boiling point of the compositions changed by less than about 2°C. The compositions exhibit azeotrope and/or azeotrope-like propertiesover this range.

TABLE 1 HFO-1234/HFC-134a compositions at 14.41 psia Wt. % Wt. % Trans-T (C.) 134a 1234ze −25.288 100.00 0.00 −25.522 99.07 0.93 −25.581 95.014.99 −25.513 91.74 8.26 −25.444 86.21 13.79 −25.366 77.87 22.13 −24.92667.47 32.53 −24.633 61.67 38.33 −24.291 55.23 44.77 −23.998 51.05 48.95

Example 2

An ebulliometer consisting of vacuum jacketed tube with a condenser ontop which is further equipped with a Quartz Thermometer is used. About35 g HFC-125 is charged to the ebulliometer and then HFO-1234ze is addedin small, measured increments. Temperature depression is observed whenHFO-1234ze is added to HFC-125, indicating a binary minimum boilingazeotrope is formed. From greater than about 0 to about 24 weightpercent HFO-1234ze, the boiling point of the composition changed byabout 2° C. or less. The binary mixtures shown in Table 1 were studiedand the boiling point of the compositions changed by less than about 6°C. The compositions exhibit azeotrope and/or azeotrope-like propertiesover this range.

TABLE 2 HFO-1234/HFC-125 compositions at 14.40 psia Wt. % Wt. % Trans- T(C.) 125 1234ze −48.446 100.00 0.00 −48.546 99.42 0.58 −48.898 96.353.65 −48.697 92.27 7.73 −47.842 84.68 15.32 −46.686 77.49 22.51 −44.85668.02 31.98 −43.177 59.57 40.43 −42.513 56.97 43.03

Example 3

An ebulliometer consisting of vacuum jacketed tube with a condenser ontop which is further equipped with a Quartz Thermometer is used. About17 g HFC-152a is charged to the ebulliometer and then HFO-1234 is addedin small, measured increments. Temperature depression is observed whenHFO-1234 is added to HFC-152a, indicating a binary minimum boilingazeotrope is formed. From greater than about 0 to about 30 weightpercent HFO-1234, the boiling point of the composition changed by about0.8° C. or less. The binary mixtures shown in Table 1 were studied andthe boiling point of the compositions changed by less than about 1° C.The compositions exhibit azeotrope and/or azeotrope-like properties overthis range.

TABLE 3 HFO-1234/HFC-152a compositions at 14.39 psia Wt. % Wt. % Trans-T (C.) 152a 1234ze −23.455 100.00 0.00 −23.504 99.34 0.66 −23.631 96.833.17 −23.778 94.99 5.01 −23.817 87.22 12.78 −24.160 81.49 18.51 −23.79770.59 29.41

Example 4

An ebulliometer consisting of vacuum jacketed tube with a condenser ontop which is further equipped with a Quartz Thermometer is used. About18 g HFO-1234 is charged to the ebulliometer and then HFC-227ea is addedin small, measured increments. Temperature depression is observed whenHFC-227ea is added to HFO-1234, indicating a binary minimum boilingazeotrope is formed. From greater than about 0 to about 53 weightpercent HFC-227ea, the boiling point of the composition changed by about0.7° C. or less. The binary mixtures shown in Table 1 were studied andthe boiling point of the compositions changed by less than about 1° C.The compositions exhibit azeotrope and/or azeotrope-like properties overthis range.

TABLE 4 HFO-1234/HFC-227ea compositions at 14.44 psia Wt. % Trans- Wt. %T (C.) 1234ze 227ea −18.124 100.00 0.00 −18.310 98.87 1.13 −18.506 93.236.77 −18.653 86.62 13.38 −18.741 76.24 23.76 −18.555 66.40 33.60 −18.35958.18 41.82 −18.114 52.63 47.37 −18.055 46.56 53.44

What is claimed is:
 1. An azeotrope-like composition consistingessentially of (a) trans-1,3,3,3-tetrafluoropropene (trans HFO-1234ze)and (b) 1,1,1,2-tetrafluoroethane (“HFC-134a”), said HFC-134a beingpresent in the azeotrope-like composition in a range of from about 25 wt% to less than 100 wt %, wherein said composition range includes aminimum boiling azeotrope having a liquid composition componentconcentration equal to the vapor composition component concentration,whereby at a pressure of about 14.4 psia said azeotrope-like compositionhas a boiling point of −25° C.+/−3° C.
 2. A heat transfer compositioncomprising the azeotrope-like composition of claim
 1. 3. The heattransfer composition of claim 2 wherein said azeotrope-like compositionhas a boiling point of from about −26° C. to about −23° C. at a pressureof about 14.4 psia.
 4. A heat transfer system comprising the heattransfer composition of claim
 3. 5. An air conditioning systemcomprising the heat transfer composition of claim
 3. 6. A refrigerationsystem originally designed for use with HFC-134a and comprising the heattransfer composition of claim
 2. 7. The heat transfer composition ofclaim 2 wherein said heat transfer composition is non-flammable.
 8. Theheat transfer composition of claim 7 further comprising a lubricant. 9.The heat transfer system of claim 4 wherein said heat transfer system isselected from the group consisting of an automotive air conditioningsystem, a heat pump system, and a stationary air conditioning system.10. The heat transfer system of claim 4 comprising a chiller.
 11. Theheat transfer system of claim 4 wherein said chiller comprises acentrifugal compressor.
 12. The heat transfer system of claim 4comprising a commercial refrigeration system.
 13. The heat transfercomposition of claim 2 having a global warming potential (“GWP”) lessthan about
 1000. 14. The heat transfer composition of claim 2 having aGWP less than about
 500. 15. The refrigeration system of claim 6 whereinsaid heat transfer composition has a GWP less than about
 1000. 16. Therefrigeration system of claim 6 wherein said heat transfer compositionhas a GWP less than about
 500. 17. The heat transfer system of claim 11wherein said heat transfer composition has a GWP less than about 1000.18. The heat transfer system of claim 12 wherein said heat transfercomposition has a GWP less than about 500.